Motors with cylinder-piston-rod-crank are the popular method of converting pressure into rotational forces. These motors have essentially reached a maximum efficiency in the original internal combustion, four stroke configuration. The compression stroke diminishes the crankshaft torque and the articulating piston rod is inefficient as its direction of force is largely outside that of the piston. High compression ratios and extreme cylinder head pressures are applied with little initial effect on a crank that is parallel to the force direction. Over half of this high pressure has dissipated before the crank reaches its full effective length. This high pressure generation and containment requires large bulky engine blocks with special alloys and elaborate heat dissipation methods. Electronic controls for precise timing and fuel metering along with the use of alternative fuels and electric motor drives, innovative transmissions and differentials have allowed this system to reach its maximum efficiency.
Two stroke engines are more pollutive and less efficient and require high rpm/fuel use to produce effective torque. The only method that these engines have of increasing rotational force is the introduction of additional fuel/air into the cylinders and increasing the rpm per distance traveled through transmissions. i.e. more fuel use.
Various types of external combustion engines exist that have a combustion expansion chamber. See U.S. Pat. No. 5,275,134 to Springer. This and similar efforts to convert force into torque have incorporated wobble and/or stash plates which are suited only for limited use and force. Springer describes a two stroke ICE(internal combustion engine) with oscillating cylinders with a separate intake and power pistons. One of the advantages cited is that of the piston rod being always aligned with the piston force, but again, the limitation of all force being applied to a central, small crankshaft.
U.S. Pat. No. 6,453,869 to Moore describes an ICE with variable crank ratio to extend dwell time at top dead center of firing/power stroke plus align piston rod more closely with force. The extra gear apparatus was costly to manufacture and added weight to engine and required extra maintenance. The Moore patent was cited in both U.S. Pat. No. 7,185,557 to Venettozzi; and U.S. Pat. No. 6,971,342 to Grabbe. The Venettozzi patent described altering the crank throw to an epitrochoidal effect and the Grabbe patent described changing the crank throw by bearing displacement mechanism. A primary problem again is the large, heavy block and all force applied to small crankshaft.
U.S. Pat. No. 4,276,951 to Smitley describes a vehicular energy storing system. Smitley describes a basic ICE, with the inefficient, bulky, weighty and encumbrances of a cooling system and transmission, that uses a process of converting fuel (gasoline) into gaseous pressure and transmits the pressure into rotational force that is manipulated (increased by additional rpm, or reversed) by a separate transmission and then divided by a differential before reaching the drive wheel axles. The rotational force begins inside a cylinder containing a piston and transmits this pressure to a rotatable crank. This “power stroke” is the third transit of the cylinder length by the piston in the 4 cycles required in the standard ICE used in vehicles today.
The fourth cycle begins after the power stroke when the still burning fuel mixture is forced out of the cylinder by the reverse movement of the piston. This pressure is estimated to be approximately 200 psi (down from 1000 psii+− at top dead center, TDC). This tremendous heat and pressure is required to give this process its peak efficiency in the ICE system, but is largely negated by the required strength and bulk of the containment members and elaborate cooling system.
The first cycle begins when the piston again reaches TDC as a valve opens and allows fresh air to be sucked into the cylinder by the downward movement of the piston. The second cycle begins when the piston again reverses direction and begins the compression stroke, reaching 10:1 ratio or more. Near TDC, an idle fuel volume is injected into this pressurized air and ignited, producing the power stroke. Two crank revolutions are required to produce these 4 cycles—one power stroke. The idle fuel volume is calculated to overcome the compression stroke and friction of the two crank revolutions. After starting, the ICE remains running, using one idle fuel volume for each two crank revolutions per cylinder. To accelerate the crank rpm, additional fuel is injected into the power stroke.
The ICE in the Smitley patent is limited to revolving in one direction only. The torque generated by the crankshaft is not sufficient to propel the vehicle without a gear and clutch system which multiplies the crank rpm delivered to the drive wheels. The ICE fuel to gaseous pressure process cannot tap and store vehicle inertia when braking to later aid in acceleration. The Smitley patent attempts to solve this problem and increase efficiency by harnessing the drive shaft rpm and direct this rotational force via a heavy gear and clutch system to a large and heavier flywheel which will rotate until its inertia is tapped via the gear system to aid in the acceleration of the drive shaft rpm.
In addition to the above cited patents, an experimental research team focused on the advantages of the variable stroke engine which can be found in APPLIED ENERGY. Vol. 77, Issue 4, on Apr. 4, 2004, pg 447-463.
Thus, the need exists for solutions to the above problems with the prior art.